There is mounting evidence showing that interactions with an animal can have a variety of positive effects on the well-being of humans. However, most of this information emanates from studies done on adults with profound social and mental issues, or children disabilities. The long-range goal associated with this research is to offer sound data about pet ownership, to enhance the instruments to be used in the National Child Study (NCS). The objective of this particular application is to measure the association between responsible pet ownership and the ability of a child to achieve and maintain the control of his or her type 1 diabetes. Our central hypothesis is that children who actively engage in care activities with a pet will be more likely to apply the rigorous self-care responsibilities required for the control of the disease. This hypothesis will be tested by pursuing one goal: to measure the impact of responsible pet ownership on the attainment and maintenance of glycemic control in children and adolescents with type 1 diabetes mellitus. The proposed study will be done in the form of 1) a case-control study, where active patients from the Pediatric Diabetes clinic database at the University of Massachusetts Memorial Medical Center will be enrolled with respect to their diabetes control status; 2) a cohort study, where incident patients from the same clinic will be recruited with respect to their pet ownership status, and followed prospectively untl they achieve diabetes control, or not; and 3) a randomized trial, where one half of the children who have yet to control their diabetes will be asked to look after a pet fish. The approach is innovative because it will compare data for a large number of children, investigating an association that has yet to be described. The proposed research is significant because it is expected to yield good quality information on which to base decisions about the adoption of a suitable pet in households where there is a diabetic child. This is important because such recommendations might contribute to a lessening of the individual and collective burden of juvenile diabetes.